Environment

Surviving the Great Indoors: The Pros and Cons of Living in an A/C World

There's no doubt that air-conditioning can save your life, but as heat waves increase in the future, should we all be armed with A/C?

Editor's Note: The following is an excerpt fromLosing Our Cool: Uncomfortable Truths about Our Air-Conditioned World (and Finding New Ways to Get Through the Summer)by Stan Cox (New Press). You can also read arecent piecefrom Cox about tips for staying cool without air-conditioning.

Eddie Slautas turned down his neighbors' repeated offers to install a window air conditioner in his Chicago apartment. Even when they said they'd help him pay the difference in his utility bill, the 74-year-old demurred. "Why should I make my electric bill higher?" he asked. "The fan is good enough." Then came a fierce midsummer heat wave. On the night of July 30, 1999, the neighbors found Slautas dead. The fan was running, blowing hot air across his body. He was one of 103 Chicagoans killed by the heat that week.

On the last night of July 2006, a Commonwealth Edison power cable running beneath the city of Chicago failed, putting 3,400 customers in the dark. The next day, as temperatures reached 100 degrees on the fifth day of a blistering heat wave, 1,300 people had to be evacuated from high-rise residential buildings in the area. Their apartments had become saunas, so they took refuge in air-conditioned shelters. Resident Lutricia Somerville, who had resorted to spending much of the night in her parked truck with the air conditioner running, told a reporter, "It's just like Hurricane Katrina." Those trapped in the heat must indeed have felt some of the desperation that had hit New Orleans residents 11 months earlier. But the outage was short-lived, and this time no one died or suffered serious medical problems.

Life and Death on Heat Island

In June 2009, the U.S. Global Change Research Program -- a cooperative effort by 13 federal agencies and the White House-- issued an alarming 188-page progress report on the pace of global warming. Among many dire predictions was a forecast of deteriorating human health. Thomas Karl, director of the National Climatic Data Center and the report's principal author, said health was the issue sparking the most discussion among the agencies and leading to the least certain conclusions; however, the report confidently predicted increasing rates of heat-related illness and mortality, and that higher temperatures, along with air pollution, would cause the already accelerating rates of asthma and other respiratory ailments to rise even faster.

Heat waves continue to plague Chicago, but the city is better prepared than it once was. Its public health officials are determined to avoid a replay of the bitter experience of July 1995, when more than 550 city residents were killed by record-breaking heat. Most of those who died had no air-conditioning, or if they did, they could not afford the electricity to run it. The record numbers of air conditioners that were switched on triggered more than 1,300 failures in the electricity supply system, many of them caused by overheating of overloaded transformers. A series of blackouts hit both rich and poor neighborhoods, but the bulk of the casualties occurred in lower-income areas.

Longer, more intense heat waves hit Chicago in 1931 and 1936 but killed far fewer people. That difference between the 1930s and 1990s has puzzled experts; residential air-conditioning was virtually unheard of in the 1930s, and the inner city's population was only slightly smaller then than it is today. However, the average age of residents has increased, there is a lot more concrete to hold the heat, and analysts at the Midwestern Climate Center have suggested that people, especially older people, have become more afraid of crime and more reluctant to leave doors and windows open or to sleep outdoors (as many did in the 1930s). The analysts went on to suggest that "many people have also forgotten how to 'live and function' with high temperatures."

Air-conditioning has been credited with huge improvements in the health of the U.S. population. Ray Arsenault provided a partial list of benefits that were realized in the first few decades of climate control: "Air-conditioning has reduced fetal and infant mortality, prolonged the lives of thousands of patients suffering from heart disease and respiratory disorders, increased the reliability and sophistication of micro-surgery, facilitated the institutionalization of public health, and aided the production of modern drugs such as penicillin."

Air-conditioning can also be an important tool in dealing with the kinds of weather crises that may become more frequent. Within the first few hours of the extensive August 2003 power blackout in the Great Lakes and Northeast, emergency rooms were overwhelmed with patients, a large proportion of them suffering in one way or another from heat stress. Most were rushed into air-conditioned shelters, where they recovered. There is also evidence that air-conditioning provides routine protection against illnesses caused by allergens, air pollution and mosquito-borne pathogens and parasites.

Despite conflicting research results -- some statistics show that air-conditioning has reduced heat-related death rates while others, as we will see, find air-conditioning's effects swamped out by socioeconomic forces -- the most direct and quantifiable claim made for air-conditioning is that it can reduce the death toll during a heat wave if broad access is ensured.

The nation's average temperatures dropped following the hot 1930s, but heat waves made a comeback during the age of air-conditioning. From 1949 to 1995, the frequency of heat waves increased 20 percent, and the trend has steepened since; matters are predicted to worsen. The Global Change Research Program report, for one, is forecasting that "extreme heat waves, which are currently rare, will become much more common in the future."

In a highly unusual incident that we can only hope is never repeated, an extraordinarily large, intense mass of heat and humidity in August 2003 reportedly killed 35,000 to 52,000 people in Europe. Most of the victims lived in places that normally see much milder summer weather and have few air-conditioners or other means of defense against severe heat. Part of the increase in superheated weather in cities across the globe can be attributed to the heat-island effect, but these early days of global warming may already be generating more heat emergencies.

Average over the past century, heat and humidity have killed far more Americans than any other type of adverse weather. In 44 of the largest U.S. cities, heat waves kill more than 1,800 people per year on average, but the annual toll rises and falls steeply, depending on whether or not there was a major-league heat wave in a given year.

A 2003 study of 28 U.S. cities suggests that the increase in heat-wave deaths between the 1930s and 1990s in Chicago may have been an exception; average numbers of heat-related deaths dropped by 59 percent from the 1960s and 1970s to the 1980s and continued falling through the 1990s. The study concluded, "This systematic desensitization of the metropolitan populace to high heat and humidity over time can be attributed to a suite of technologic, infrastructural, and biophysical adaptations, including increased availability of air-conditioning." A nationwide study that used statistical techniques to eliminate the effects of other socioeconomic factors found that access to central air-conditioning reduced death rates by 42 percent during heat waves that occurred between 1980 and 1985. Room air conditioners, in contrast, had no effect, except in the smallest, one- to three-room dwellings, where a window unit "may be seen as nearly equivalent to central air-conditioning."

The health benefits of air-conditioning have not been shared evenly. Historically, the most obvious disparities have been between races. In four northern cities surveyed between 1986 and 1993, 41 percent of white households had air-conditioning, compared with 16 percent of black households. Heat waves in Minneapolis and Pittsburgh killed black residents at six to seven times the rate at which they killed whites during that period. Almost two-thirds of the difference in heat-related deaths between the races was linked to differences in availability of central air-conditioning. Central heating didn't have the same effect; racial differences in death-rate peaks during winter cold spells were much smaller.

People who enjoy easy access to central air-conditioning tend to assume that surviving killer heat is no more than a matter of motivation. One such person was Chicago's human services commissioner Daniel Alvarez. In the wake of the city's 1995 heat crisis, he told the press that its victims were "people who die because they neglect themselves." But heat kills people like Eddie Slautas not because they are lazy or stubborn but because they are under economic stresses. People with central air, who almost always survive heat waves, tend to have higher incomes; larger, newer houses; better plumbing; and higher education levels. All of those factors are also associated with lower heat-related mortality. Heat death rarely visits well-to-do neighborhoods; its victims are typically found in economically forgotten, concrete-rich, vegetation-free nooks and crannies of the larger cities. In the 21st century, air-conditioning has become almost universally available, yet heat waves continue to kill.

Reducing that death toll will require changing communities, not just individuals. One of several studies of the 1995 Chicago heat wave concluded that "features of neighborhoods on a relatively small geographic scale (e.g., amount of pedestrian traffic, small shops, public meeting places) affect survival rates [positively]." Marie O'Neill of the University of Michigan's School of Public Health, the lead author of one of the studies and of the research that produced the numbers in Table 5, says that while "air-conditioning is protective in the home setting," when heat waves come, home climate control is "less holistic and, of course, the more climate-damaging alternative in the long term." Both her own observations and the human experience documented in Klinenberg's history of the 1995 tragedy, Heat Wave, emphasize "the value of an overall healthier, more equitable, cohesive neighborhood and society for the most vulnerable residents," according to O'Neill.

Christian Warren is troubled by our dependence on artificial climate control as a remedy for ills that run much deeper: "Now you see air-conditioning pitched in the medical literature as an environmental justice issue, because it can save lives during heat waves. It has come to be regarded as another biotechnological tool. They aren't asking what really kills people. What about isolation, economic stress, crime, and paranoia about crime? You can easily imagine a couple staying shut away in their air-conditioned apartment during a hot spell, uninterested in checking on their elderly next-door neighbor, who could be dying of heat stroke."

If current greenhouse emissions continue, excess heat-related deaths in the United States could climb into the range of 5,000 per year by 2050. The EPA suggests that public health officials prepare for more frequent "extreme heat events." Recommended actions include designating air-conditioned public buildings and some private buildings like movie theaters and shopping malls as cooling shelters, providing public transportation to the shelters, and (in vaguely sinister-sounding terms) targeting homeless people for "protective removal" to cooled spaces.

Cooling centers have become a common and highly effective strategy for protecting residents of big cities, not only against killer heat waves but against more routine hot weather as well. But for people already dealing with health problems, it's not easy to find the right temperature balance in a public cooling space. For example, during a mid-August 2009 hot spell, some of those taking refuge in a well-air-conditioned senior citizens' center in Brooklyn were found to be covering their shoulders with sweaters in order to stay warm. One of them, 78-year-old arthritis sufferer Vida Ebrahim, told the New York Times, "My apartment is so hot because the ceiling is low, so it keeps the heat. Oh my God, it's murder. But the air-conditioner, it gives me so much pain in my shoulders, in my knees."

Stan Cox is a plant breeder and writer in Salina, Kansas. His book "Losing Our Cool: Uncomfortable Truths about Our Air-Conditioned World," will be published next June by The New Press.